Quest M3 Solid vs. Perforated Drum

#1: Post by **jjack** » April 3rd, 2016, 3:21 pm

I ordered a perforated drum directly from the factory for my Quest M3:

With a local coffee (grown in Antioquia, Colombia) I did a base roast at 8.5 amps and a fan setting of 3 with 200gr. batch on the solid drum. I did not vary power or fan speed during the roast. I then repeated with the same amount of coffee with the perforated drum. Here are the two roasts (background is the base roast):

When I disassembled the roaster I found the BT probe to be bent upward, probably due to my botched nut roasting attempt. I straightened the probe when reassembling so there could be a difference between the solid vs. perforated roast. Still, the perforated roast seems to drop temperature faster and have a higher RoR during drying phase. Afterwards, they both seem to be similar.
I will have to start playing with varying power and fan speed in subsequent roasts to see if it is more responsive. I will keep posted.

#2: Post by **happycat** » April 3rd, 2016, 4:46 pm

Thanks for sharing this. Will be great to learn more! I hope to mod my Quest drum when I visit family in a month.

#3: Post by **AssafL** » April 4th, 2016, 2:59 am

You tried nuts? I tried Chestnuts (M3 does looks like the perfect chestnut roaster) but the orifices are too narrow so I couldn't get them out....

April 4th, 2016, 10:21 am

Well, they were Brazilian nuts cut in chunks, put still hard to get in and out. I had tried peanuts before and thought that went well until I found many in the exhaust tube while I was changing the drum, which were WELL past optimum roasting point.

Here is a photo of both coffees roasted. The one on the right is the perf one.

Seems to me both results are comparable. If I had to point a difference, its the perforated one seems a more even roast, but not sure the difference is big. As I said before, probably the biggest difference will be in temperature responsiveness.

Maybe some of the other guys who've done drum mods can shed some light in the differences.

#5: Post by **AndreG** » April 4th, 2016, 5:47 pm

Could you share the details of the roast: weight, initial temp, temps, fan...

April 5th, 2016, 2:49 pm

AndreG,
Here are the Roasting reports:
SOLID DRUM BATCH:
Weight: 200.0g
168.0g (16.0%)

CHARGE: BT 207°C
ET 202°C
TP: 01:00 (115°C)
DRY: 03:40 (149°C)
FCs: 08:52 (194°C)
FCe: 10:42 (210°C)
SCs: 11:47 (220°C)
SCe: --
DROP: 12:23 (227°C)
COOL: 15:43 (03:20m)
MET: 236°C
RoR: 9°C/m
ETBTa: 288 [2410-2122]
CM: 0.2/0.2°C

Drying: 03:40 (30%)
12.6°C/min
113 [618-505]
Grassy/OK
Maillard: 05:11 (42%)
8.7°C/min
128 [1007-879]
Toasty/OK
Development: 03:30 (28%)
9.5°C/min
47 [785-739]
Acidic/OK
Cooling: 03:20 (27%)
Fracturing/Sweet

PERFORATED DRUM BATCH
Weight: 200.0g
167.0g (16.5%)

CHARGE: BT 208°C
ET 224°C
TP: 00:50 (88°C)
DRY: 03:35 (146°C)
FCs: 08:52 (201°C)
FCe: 10:22 (210°C)
SCs: 11:32 (222°C)
SCe: --
DROP: 12:28 (232°C)
COOL: 15:54 (03:25m)
MET: 246°C
RoR: 12°C/m
ETBTa: 536 [2665-2129]
CM: 16.7/7.3°C

Drying: 03:35 (29%)
21.2°C/min
270 [698-428]
Grassy/OK
Maillard: 05:16 (42%)
10.3°C/min
191 [1120-929]
Toasty/OK
Development: 03:35 (29%)
8.7°C/min
75 [847-771]
Acidic/OK
Cooling: 03:25 (27%)
Fracturing/Sweet

In both cases power was constant at 8.5 Amps and Fan setting 3.
Hope that helps.

#7: Post by **AndreG** » April 5th, 2016, 5:55 pm

WOW! That exceed what I had in mind. Thank you for sharing. And yes, it does help to choose witch modification between the present options.

#8: Post by **FotonDrv** » April 6th, 2016, 10:02 am

Carlos, what size are the holes you put into the drum?

Did you cut out the louvers in the case behind the fan?

#9: Post by **AssafL** » April 6th, 2016, 10:26 am

Why cut out the louvers?

#10: Post by **FotonDrv** » April 6th, 2016, 10:37 am

Less resistance to air flow. If they get a buildup of crud then they are restricting air. Obviously keep everything clean, but just saying they are in the way.